Defining Checks

This page is an introduction to performing checks on a JSON data set. It provides information on various types of checks that can be performed and how to define conditions for those checks. The examples on this page utilize a sample data set, which is provided in the following snippet:

{
  "store": {
    "book": [
      {
        "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95,
        "tags": ["book", "Rees", "reference", "Sayings"]
      },
      {
        "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99,
        "tags": ["book", "Waugh", "fiction", "Sword"]
      },
      {
        "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99,
        "tags": ["book", "Melville", "fiction", "Moby"]
      },
      {
        "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99,
        "tags": []
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

References

For a ref in a JSON evaluator config file you should always use a jsonPath expression that returns an array of the objects you are interested in. Hereby you can use the [*] operator to get all objects of an array. But be careful what you actually need: if you want to check, for example, if the tags of any book contains book you could get all tags via $.store.book[*].tags[*]. This results in:

[
  "Rees",
  "reference",
  "Sayings",
  "Waugh",
  "fiction",
  "Sword",
  "Melville",
  "fiction",
  "Moby"
]

But if you want to check if the tags of each book contains book, you need to get the tags of each book. This can be done via $.store.book[*].tags. This results in:

[
  ["book", "Rees", "reference", "Sayings"],
  ["book", "Waugh", "fiction", "Sword"],
  ["book", "Melville", "fiction", "Moby"],
  []
]

Now we could use all(ref, "($).includes('book')") to check if all books have the tag book. Alternatively you could use the jsonPath expression $.store.book as ref and use all(ref, "($.tags).includes('book')") to check if all books have the tag book.

If you want to check a single object you can use ref: $ to get the root object.

To check your jsonPath syntax you can use the jsonPath online evaluator

Conditions

Simple conditions

ref: $.store.book[*]
condition: all(ref, "$.category === 'fiction'") # all values of ref with the key "category" are equal to "fiction"
condition: any(ref, "$.category === 'fiction'") # at least one value of ref with the key "category" is equal to "fiction"
condition: one(ref, "$.category === 'fiction'") # exactly one value of ref with the key "category" is equal to "fiction"
condition: none(ref, "$.category === 'fiction'") # none of the values of ref with the key "category" is equal to "fiction"

Of course you can use any other condition like: !==, >, <, >=, <=.

Array conditions

These conditions check and compare the required object value against an array of possible values:

ref: $.store.book[*]
condition: $[*].category === ["fiction", "reference"] # the categories of ref are equal to ["fiction", "reference"] (order matters)
condition: $[*].category !== ["fiction", "reference"]  # the categories of ref are not equal to ["fiction", "reference"] (order matters)
condition: ($[*].category).includes('fiction') # the categories of ref includes "fiction"
condition: ($[*].category).length == 1 # the categories of ref is an array with length 1

Concatenation

The concatenation part of the config file also has a condition field. This condition is a logical expression that is evaluated with the results of the checks and should contain references to the names of the checks e.g. check1 && check2.

If no concatenation is defined the result of the evaluation is the result of all checks concatenated with AND condition &&.

concatenation:
  condition: "has_category_check && category_check && fiction_check && none_fantasy_check"

Example

A full example of a config file can be found here.